Koral Karsan had worked for Yoko Ono for six years

Koral Karsan, 50, pleaded not guilty to four counts of first-degree attempted grand larceny last month.

New York State Supreme Court Justice Daniel Fitzgerald said there was nothing new in the case to justify releasing him.

Mr Karsan's lawyer Robert Gottlieb said at the hearing last month that he would "vigorously dispute" the charges.

Prosecutors believe Mr Karsan will try to return home to his native Turkey if given bail.

The defendant was arrested in December after allegedly threatening to release embarrassing photos and audio tapes of Ono unless she paid $2m (�1m).

Mr Gottlieb has asked the New York judge for the earliest possible trial date, possibly at the beginning of February.

The lawyer has previously accused Ono, 73, of pressuring Mr Karsan "to perform immoral and at times illegal acts" and said her "demands escalated over the years".